Question: Khan.scratchpad.disable(); Kevin sells magazine subscriptions and earns $$7$ for every new subscriber he signs up. Kevin also earns a $$33$ weekly bonus regardless of how many magazine subscriptions he sells. If Kevin wants to earn at least $$51$ this week, what is the minimum number of subscriptions he needs to sell?
Solution: To solve this, let's set up an expression to show how much money Kevin will make. Amount earned this week $=$ $ $ Subscriptions sold $\times$ Price per subscription $+$ Weekly bonus Since Kevin wants to make at least $$51$ this week, we can turn this into an inequality. Amount earned this week $\geq $51$ Subscriptions sold $\times$ Price per subscription $+$ Weekly bonus $\geq $51$ We are solving for the number of subscriptions sold, so let subscriptions sold be represented by the variable $x$ We can now plug in: $x \cdot $7 + $33 \geq $51$ $ x \cdot $7 \geq $51 - $33 $ $ x \cdot $7 \geq $18 $ $x \geq \dfrac{18}{7} \approx 2.57$ Since Kevin cannot sell parts of subscriptions, we round $2.57$ up to $3$ Kevin must sell at least 3 subscriptions this week.